The present invention relates to automatic or semi-automatic weapons and especially to a pistol design to be made substantially of polymer materials.
Pistols have generally been divided into two classes: revolvers and the automatics. Revolvers embody an element that revolves and employ a short multi-chambered cylinder positioned behind a single barrel so that the cartridge in each chamber is brought successfully into alignment with the barrel. Pulling the trigger revolves the cylinder brings a fresh cartridge in line with the hammer, locks the cylinder in place and releases the hammer to discharge the cartridge. Automatic pistols, on the otherhand, have their mechanism actuated by the energy of recoil when a bullet is fired. Cartridges are fed into the mechanism through a magazine in the butt of the pistol. The energy of recoil drives the whole superstructure of the pistol rearward on a horizontal platform built into a lower frame. A recoil spring compresses during this movement, then uncoils to force the parts back to their forward or firing position. Automatic Pistols are further divided into those that may be gas operated, straight blowback, retarded blowback and short-recoil types. The only short-lived example of a gas operated pistol was made in France and called the "Clair". This employs the usual gas port expansion chamber beneath the barrel similar to gas operated rifles with the cartridges being fed into the mechanism through a tubular magazine in the butt of the pistol. A more common design uses a straight blowback or in the case of more powerful ammunition a retarded blowback type or a short-recoil system in which the reactionary force of the bullet casing drives the bolt, hammer, and assembly rearward against a spring to cock the hammer. A spring returns the bolt assembly feeding the next cartridge into the chamber and leaving the hammer latched by a sear which in turn is actuated by the trigger to allow the hammer to drive against the firing pin. Prior pistols have generally been made of high grade steel but less expensive models have had parts such as the receiver made of various types of alloy, such as aluminum or zinc alloys but with a steel barrel, chamber and bolt. A high grade steel can withstand the temperatures and pressures generated by the firing of a bullet and the increased mass of the weapon over lighter materials reduces the recoil and the chance of an injury to the user of the weapon.
In contrast to the prior pistols, the present invention is directed toward a semi-automatic or automatic pistol made substantially of polymer materials which reduces the weight of the pistol and avoids corrosion problems and allows for the use of inexpensive injection molded parts. It has previously been thought that polymers were unsuitable for use of any major component of an automatic pistol. But by the use of high strength temperature resistant polymers in combination with a weapon assembly designed specifically for polymers, the problems have been overcome with the present invention. The present pistol can be made entirely of polymers, but would typically have metal springs. It might utilize a metal firing pin or bolt if desired.